Sort filenames naturally with Qt

c++, natural-sort, qt

Solution

If you want to use `QCollator` to sort entries from the list of entries returned by `QDir::entryList`, you can sort the result with `std::sort()`:

dir.setFilter(QDir::Files | QDir::NoSymLinks);
dir.setSorting(QDir::NoSort);  // will sort manually with std::sort

auto entryList = dir.entryList();

QCollator collator;
collator.setNumericMode(true);

std::sort(
    entryList.begin(),
    entryList.end(),
    [&](const QString &file1, const QString &file2)
    {
        return collator.compare(file1, file2) < 0;
    });

According to The Badger's comment, `QCollator` can also be used directly as an argument to `std::sort`, replacing the lambda, so the call to `std::sort` becomes:

std::sort(entryList.begin(), entryList.end(), collator);

Problem

I am reading a directories content using `QDir::entryList()`. The filenames within are structured like this: ``` index_randomNumber.png ``` I need them sorted by `index`, the way the Windows Explorer would sort the files so that I get ``` 0_0815.png 1_4711.png 2_2063.png ... ``` instead of what the sorting by `QDir::Name` gives me: ``` 0_0815.png 10000_6661.png 10001_7401.png ... ``` Is there a built-in way in Qt to achieve this and if not, what's the right place to implement it?

Original source